Every Monday, we'll show you how to do something new and simple with Apple's built-in command line application. You don't need any fancy software, or a knowledge of coding to do any of these. All you need is a keyboard to type 'em out!

For the past few iterations of OS X, Apple has included their own command line-based utility for playing audio files on the Mac. This program called "afplay" is a great way to preview audio files right from the Terminal without having to open another application on your Mac. And, because this tool uses Core Audio to play files, it can play MP3, AIFF, WAV, M4A, and other audio types (almost any audio that could be played from within QuickTime Player).